A drone helicopter will fly ahead of the Mars rover to allow it to travel further

The challenges: The helicopter will need less lift than a similar helicopter on Earth because of the low gravity. On the other hand, the thin air will make it difficult for the helicopter to provide the lifting force that is still required.

NASA's Jet Propulsion Laboratory recently announced that it is developing a small drone helicopter whose role will be to track the way for future Mars vehicles. Why do Mars rovers need such a robotic guide? The answer is that driving on Mars is really hard.

Here on Earth, robots explore the craters of volcanoes, or assist in rescues, and can be operated by remote control and joystick. This is because the radio signals reach the robot from its control center almost instantly. Driving on the moon isn't much more complicated. Radio signals traveling at the speed of light would take about two and a half seconds to make the trip to the moon and back. This delay is not long enough to interfere with remote control driving. In 1970, Soviet Crimean controllers drove lunar vehicles from landers to Nankhud this way, successfully exploring more than 40 kilometers of lunar territory.
Driving on Mars is much more difficult, because it is much further away. Depending on its position relative to the Earth, signals take between 8 and 42 minutes for a round trip. Therefore pre-programmed instructions must be sent to the robotic vehicle that is on the surface and then it makes the journey by itself. Every move on Mars requires hours of careful planning. The images taken by the depth cameras of the vehicles were carefully examined by engineers. Images from spacecraft orbiting Mars sometimes provide additional information.
It will be possible to program a robotic vehicle to carry out a list of driving commands from Earth, and in addition it can use images taken by its navigation cameras and processed on the local computer to measure speed and identify obstacles or hazards on its own. He will also be able to design his safe trait for the specified purpose.

Spirit and Opterionity could travel up to 124 meters per hour in navigation from Earth. When the spacecraft actively guides itself with its cameras, progress is safer, but much slower because of the image processing required. He will only be able to move forward about 10 meters per hour. This method must be used whenever the vehicle does not have a clear picture of the route ahead, which often happens in the case that the vehicle is traveling in difficult and mountainous terrain.
Curiosity's longest drive in one day was 144 meters, and Opportunity's longest drive was 224 meters.
If ground controllers can get a better picture of the road ahead, they will be able to craft instructions that allow the future robotic vehicle to safely travel much greater distances in a day.
This is where the idea of ​​a drone helicopter fits in. The helicopter will be able to fly in front of the car every day. Images produced from its aerial vantage point will be an invaluable treasure for ground controllers and will allow them to identify points of scientific interest, and plan driving routes to get there.

A helicopter flying on Mars will have special challenges that drones on Earth do not have. On the one hand, the gravity of Mars is only 38% of that of the Earth, so the helicopter will not have to generate lift like helicopters of similar mass on Earth. On the other hand, the propeller blades will be required to create the lifting force that is still needed, by pushing air downwards. This is a more difficult task on Mars than on Earth because the Martian atmosphere is very thin - about one percent of the density of the Earth's atmosphere at sea level. In order to catch enough air the propeller blades would have to spin very fast or be very large.
The helicopter must be able to fly on its own, using pre-programmed instructions, and maintain a stable flight on a pre-defined route. It must be able to take off and land on the rocky terrain of Mars, and finally, it must be able to survive the harsh conditions of Mars, where the temperature drops to 100 degrees Celsius and below every night.

JPL engineers are developing a helicopter with a mass of one kilogram, a fraction of the mass of the Curiosity vehicle which weighs 900 kg. Its compressor blades extend 1.1 meters from end to end and it is capable of rotating 3,400 revolutions per minute. The entire size of the helicopter itself is about the size of a tissue box.
The helicopter will be powered by solar energy, with its solar cells required to collect enough energy each day to allow it to fly for 2-3 minutes, and heat it at night. He will be able to fly at this time to a distance of about 500 meters to collect images and transfer them to ground control. Engineers at JPL estimate that with the help of the drone it will be possible to triple the distance that the robotic vehicle will travel in a day.

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